The present invention relates in general to a polyphase bandpass filter.
Such filters are known per se, for instance from the U.S. Pat. No. 4,914,408, and they can for instance be applied in receiver circuits for, e.g. radio applications, television applications, or telephone applications. Although such filters also know different applications, a possible application of such a filter will be explained here in more detail in the context of a receiver circuit.
An important drawback of the filter described in U.S. Pat. No. 4,914,408 is that a coupling between two filter channels is effected by means of resistors. An important aim of the present invention is therefore to provide a polyphase bandpass filter wherein such coupling resistors are omitted.